An automated dartboard system has a number of advantages, such as knowledge of when a match has commenced and when it has ended. This allows the system to use automated revenue collection means, such as are used in video or arcade games.
As shown by the art in this field, many attempts have been made to create such a system. One popular system has been the type shown in British patent specification 1 532 744 of Jones et al. filed May 30, 1977, and published Nov. 22, 1978. Jones discloses a system employing plastic tipped darts and an array of target plates moulded with a large number of closely spaced holes corresponding substantially in size to that of the tip. When the dart is thrown at the board, the tip enters into one of the holes and remains in the hole until removed by one of the players. For automated scoring, a given target plate is slidably supported and, when a given target plate is struck by a dart, the plate slides inwardly to effect closure of an electrical switch contact which directs a signal to a scoring register.
Obviously, the Jones system is not designed to employ regulation grade metal tipped darts of the type preferred by serious dart players. The games are not sufficiently realistic for a wide segment of the market. In addition to the modifications required for reception and retention of grade metal tipped darts, the switches used and the plastic target plate struck by a dart are typically not strong enough to withstand continuous heavy impact from grade metal tipped darts.
Holt et al. in U.S. Pat. No. 4,651,998 issued Mar. 24, 1987 discloses a safe tip dart system such as that in Jones et al. Holt et al add a bullseye detection mechanism wherein the dart board deforms, or alternatively a plate slides within the board, to actuate a contact switch that causes a timer circuit to activate an audible alarm. This provides an additional attraction for playing the game. The Holt et al bullseye provides only a means to actuate a bullseye segment and only in conjunction with an all plastic safe tip dart board. As safe tip darts are being used, wear of the segments is not a factor, and no means is discussed for lengthening time between replacement or for facilitating replacement.
Automated regulation dart systems are shown in the following U.S. Pat. No. 4,852,888 issued Aug. 1, 1989 to Ross et al; U.S. Pat. No. 4,244,583 issued Jan. 13, 1981 to Wood et al.; U.S. Pat. No. 4,014,546 issued Mar. 29, 1977 to Steinkamp; U.S. Pat. No. 3,677,546 issued Jul. 18, 1972 to Oetiker; U.S. Pat. No. 3,275,321 issued Sep. 27, 1966 to Forest; U.S. Pat. No. 3,101,198 issued Aug. 20, 1963 to Williams. Dart conductive systems have a first conductive layer part of the way into the segment and a second conductive layer further into the segment. The conductive layers are at two different potentials. When the dart enters the segment it pierces the first layer and the second layer which causes current to flow between the layers and indicates the location of the dart. Ross et al., Forest and Williams disclose modified systems of this type.
Dart conductive systems wear out in the conductive layers as they are continually pierced. As well, darts may not pierce both layers and a score will not be recorded. This can happen when the dart has insufficient energy to reach both layers or the dart enters at an angle. It is also desirable to have the dart create an impulse contact, rather than a constant contact between the conductive layers. This simplifies the operation of circuitry in the system. For a system that operates on a continuous contact see Wood et al. Most dart conductive systems use a mechanical means of moving the dart from contact with one of the layers or moving one of the layers from contact with the dart. This adds complexity to the mechanical operation of the system.
U.S. Pat. Nos. 5,486,007 and 5,613,685 issued (on Jan. 23, 1996 and Mar. 25, 1997, respectively) to the inventor et al. disclose an automated dart board which overcome the shortcomings listed above. This dart board describes a target for darts that has a conductive rigid web made up of concentric rings intersecting spokes emanating from the second to the innermost ring. The spokes define sectors, while the rings define segments within each sector. Conductive blocks, made up of a metallic cup having contacts protruding from its bottom and containing a rubberized cork insert, fill in the segments of the web. Beneath each cup is a silicon foam cushion cut away between the contacts and a pad on a printed circuit board (“PCB”). The pads are each connected to circuitry that senses when a dart hits an insert causing the corresponding cup to slide within the web and contact a pad. The circuitry, by way of piezoelectric sensors, also determines if a dart has impacted on or near the target and checks to see if the target has polled a segment that indicates a hit on the target, failing which the target indicates that the dart missed the target. The circuitry also senses the rotational orientation of the target and sets the basic scores of the segments accordingly, allowing the target to be periodically rotated to reposition segments in sectors of heavy use to sectors of lighter use.
This system requires that the conductive web, of a relatively large area, be held at a known voltage (ground or voltage high). An electrostatic charge (ESD for electrostatic discharge) builds up on the top of surface of the conductive cups. This charge may affect the sensitive low voltage electronic circuitry mounted on the printed circuit board underneath.
Other perceived deficiencies or improvements may include the higher cost and heavy weight of a metal conductive web as opposed to a cheaper and lighter non-conductive plastic or composite web; the continued need to have a switching device that will withstand the impact of metal grade steel tip darts while still maintaining its dual dart (i.e. steel and plastic) feature.
It is an object of the invention to address these perceived deficiencies in the field or other needs as will become evident from the following description.